Systems and Methods for Stimulating a Subterranean Formation

ABSTRACT

Systems and methods for stimulating a subterranean formation. The methods may include flowing, with a carrier fluid stream, an autonomous perforation device within a casing conduit that is defined by a casing string that extends within a subterranean formation. The methods further may include retaining the autonomous perforation device within a target region of the casing conduit, flowing a stimulant fluid within the casing conduit and past the autonomous perforation device, and/or stimulating, with the stimulant fluid stream, a portion of the subterranean formation that is downhole from the autonomous perforation device. The systems may include the autonomous perforation device, which may include a perforation assembly, a motion-arresting assembly, and a fluid flow conduit. The systems also may include a hydrocarbon well that includes a wellbore, the casing string, and the autonomous perforation device.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application 61/920,228, filed Dec. 23, 2013, entitled SYSTEMS AND METHODS FOR STIMULATING A SUBTERRANEAN FORMATION, the entirety of which is incorporated by reference herein.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to systems and methods for stimulating a subterranean formation, and more particularly to an autonomous perforation device that defines a fluid flow conduit and/or to systems and methods that utilize the autonomous perforation device to stimulate the subterranean formation.

BACKGROUND OF THE DISCLOSURE

Perforation devices may be utilized to perforate a casing string during completion of a well. The perforation devices may be located within a casing conduit, which is defined by the casing string. The perforation devices may be actuated to create one or more perforations at a given location along a length of the casing string. Stimulant fluid may be flowed through the casing conduit, through the one or more perforations, and into the subterranean formation to stimulate regions of the formation in the vicinity of the one or more perforations.

The perforation devices generally fall into two classes: wireline-attached perforation devices and autonomous perforation devices. Wireline-attached perforation devices are in mechanical communication with a surface region via a wireline and typically include a plurality of perforation charges. The plurality of perforation charges may be utilized to create one or more perforations at a plurality of locations along the length of the casing string, and the wireline-attached perforation device may be moved within the casing conduit via the wireline. For example, the wireline-attached perforation device may be utilized to perforate a first region of the casing string to permit stimulation of a first zone of a subterranean formation. Subsequently, the wireline-attached perforation device may be moved in an uphole direction and utilized to perforate a second region of the casing string to permit stimulation of a second zone of the subterranean formation that is uphole from the first region of the subterranean formation. This process may be repeated any suitable number of times, with the wireline-attached perforation device remaining within the casing conduit and ready to create additional perforations until each of the plurality of perforation charges has been discharged. The wireline-attached perforation device then may be removed from the casing conduit, and a new, or recharged, wireline-attached perforation device may be located within the casing conduit and utilized to create additional perforations.

In contrast, autonomous perforation devices generally are one-time-use devices that only may perforate a given, or single, location along the length of the casing string. Generally, these autonomous perforation devices are flowed through the casing conduit in a fluid stream and are configured to be automatically actuated to create one or more perforations in the casing string upon flowing to a target location within the casing conduit. Subsequent to the autonomous perforation device perforating the casing conduit, the casing conduit may, at least temporarily, not include, or contain, a viable perforation device. In addition, autonomous perforation devices generally are not retained within the target location. Instead, they typically are actuated concurrent with being flowed through the casing conduit, with the activated autonomous perforation device breaking apart (fragmenting) and/or otherwise flowing to a downhole, or even a bottomhole, location.

Under certain conditions, it may be desirable to utilize autonomous perforation devices to perforate the casing string; however, the absence of a viable perforation device within the casing conduit subsequent to actuation of an autonomous perforation device may decrease an operational efficiency of wellbore completion operations. As an illustrative, non-exclusive example, during completion operations that utilize a proppant slurry stream, the absence of a viable perforation device within the casing conduit may limit an operator's options for responding to a screenout event (e.g., an unintended concentration and/or collection of particulate material, such as proppant, within the casing conduit). As another illustrative, non-exclusive example, it may be desirable to stage autonomous perforation devices at target locations along the length of the casing conduit. Thus, there exists a need for improved systems and methods for stimulating a subterranean formation using autonomous perforation devices.

SUMMARY OF THE DISCLOSURE

Systems and methods for stimulating a subterranean formation are disclosed herein. The methods may include flowing, with a carrier fluid stream, an autonomous perforation device within a casing conduit, which is defined by a casing string that extends within a subterranean formation. The methods further may include retaining the autonomous perforation device within a target region of the casing conduit, flowing a stimulant fluid within the casing conduit and past the autonomous perforation device, and/or stimulating, with the stimulant fluid stream, a portion of the subterranean formation that is downhole from the autonomous perforation device.

In some embodiments, the stimulant fluid stream is a proppant slurry stream, and the methods further include perforating the casing string with the autonomous perforation device responsive to a pressure within the target region of the casing conduit exceeding a threshold screenout pressure. In some embodiments, the methods also may include fluidly isolating the target region of the casing conduit from the subterranean formation and perforating the casing string with the autonomous perforation device responsive to the pressure within the target region of the casing conduit exceeding a threshold perforating pressure.

In some embodiments, the methods may include providing the carrier fluid stream and/or the stimulant fluid stream to the casing conduit. In some embodiments, the methods may include ceasing the providing the carrier fluid stream and/or ceasing the providing the stimulant fluid stream. In some embodiments, the carrier fluid stream is different from the stimulant fluid stream. In some embodiments, the carrier fluid stream is similar, or identical, to the stimulant fluid stream.

In some embodiments, the methods further may include releasing a sealing material into the casing conduit. In some embodiments, the sealing material is released by the autonomous perforation device. In some embodiments, the methods may include repeating at least a portion of the methods with at least a second autonomous perforation device.

The systems may include the autonomous perforation device. The autonomous perforation device may include a perforation assembly, which is configured to perforate the casing string. The autonomous perforation device also may include a motion-arresting assembly, which is configured to be selectively actuated to retain the autonomous perforation device within the target region of the casing conduit. The autonomous perforation device also defines a fluid flow conduit, which permits fluid flow between a portion of the casing conduit that is uphole from the autonomous perforation device and a portion of the casing conduit that is downhole from the autonomous perforation device when the autonomous perforation device is retained within the target region of the casing conduit. In some embodiments, the fluid flow conduit extends through the autonomous perforation device. In some embodiments, the fluid flow conduit extends between the autonomous perforation device and an interior, or inner, wall of the casing string.

In some embodiments, the autonomous perforation device is a frangible autonomous perforation device. In some embodiments, the frangible autonomous perforation device is configured to break apart subsequent to perforating the casing string.

In some embodiments, the motion-arresting assembly defines a retracted configuration and an expanded configuration. In some embodiments, the motion-arresting assembly is configured to selectively transition from the retracted configuration to the expanded configuration to retain the autonomous perforation device within the target region of the casing conduit.

In some embodiments, the autonomous perforation device includes, or defines, a plurality of fluid flow conduits. In some embodiments, the autonomous perforation device includes a plurality of fins and/or projections that defines the plurality of fluid flow conduits.

In some embodiments, the autonomous perforation device further includes a fluid conduit sealing assembly that is configured to selectively restrict fluid flow through the fluid flow conduit. In some embodiments, the fluid conduit sealing assembly includes a valve. In some embodiments, the fluid conduit sealing assembly includes a ball sealer seat that is configured to receive a ball sealer to seal or otherwise obstruct or restrict the fluid flow through the fluid flow conduit, at least from an uphole direction.

In some embodiments, the autonomous perforation device includes an autonomous control assembly that is configured to autonomously control the operation of at least a portion of the autonomous perforation device. In some embodiments, the autonomous control assembly is a mechanical autonomous control assembly. In some embodiments, the autonomous control assembly includes an electronic controller.

The systems also may include a hydrocarbon well. The hydrocarbon well may include a wellbore, the casing string, and the autonomous perforation device. The wellbore may extend within the subterranean formation, and the casing string may extend within the wellbore. The autonomous perforation device may be located within the casing conduit, which is defined by the casing string.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of illustrative, non-exclusive examples of a hydrocarbon well that may include and/or be utilized with autonomous perforation devices according to the present disclosure and/or in which the methods of the present disclosure may be performed.

FIG. 2 is a schematic representation of illustrative, non-exclusive examples of an autonomous perforation device according to the present disclosure.

FIG. 3 is a less schematic side view of an illustrative, non-exclusive example of an autonomous perforation device according to the present disclosure in a retracted configuration.

FIG. 4 is an end view of the autonomous perforation device of FIG. 3.

FIG. 5 is a side view of the autonomous perforation device of FIG. 3 in an expanded configuration.

FIG. 6 is an end view of the autonomous perforation device of FIG. 5.

FIG. 7 is a less schematic side view of an illustrative, non-exclusive example of another autonomous perforation device according to the present disclosure in a retracted configuration.

FIG. 8 is an end view of the autonomous perforation device of FIG. 7.

FIG. 9 is a side view of the autonomous perforation device of FIG. 7 in an expanded configuration.

FIG. 10 is an end view of the autonomous perforation device of FIG. 9.

FIG. 11 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 12 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 13 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 14 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 15 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 16 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 17 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 18 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 19 provides schematic representations of illustrative, non-exclusive examples of process flows that may utilize a method, a hydrocarbon well, and/or an autonomous perforation device according to the present disclosure.

FIG. 20 is flowchart depicting methods according to the present disclosure of stimulating a subterranean formation.

DETAILED DESCRIPTION AND BEST MODE OF THE DISCLOSURE

FIGS. 1-20 provide illustrative, non-exclusive examples of autonomous perforation devices 100 according to the present disclosure, of components of autonomous perforation devices 100, of process flows that may be performed with autonomous perforation devices 100, of hydrocarbon wells 30 that may include and/or utilize autonomous perforation devices 100, and/or of methods of utilizing autonomous perforation devices 100. Elements that serve a similar, or at least substantially similar, purpose are labeled with like numbers in each of FIGS. 1-20, and these elements may not be discussed in detail herein with reference to each of FIGS. 1-20. Similarly, all elements may not be labeled in each of FIGS. 1-20, but reference numerals associated therewith may be utilized herein for consistency. Elements, components, and/or features that are discussed herein with reference to one or more of FIGS. 1-20 may be included in and/or utilized with any of FIGS. 1-20 without departing from the scope of the present disclosure.

In general, elements that are likely to be included in a given (i.e., a particular) embodiment are illustrated in solid lines, while elements that are optional to a given embodiment are illustrated in dashed lines. However, elements that are shown in solid lines are not essential to all embodiments, and an element shown in solid lines may be omitted from a particular embodiment without departing from the scope of the present disclosure.

FIG. 1 is a schematic representation of illustrative, non-exclusive examples of a hydrocarbon well 30 that may include and/or be utilized with autonomous perforation devices 100 according to the present disclosure. Hydrocarbon well 30 includes a wellbore 32 that extends within a subterranean formation 22 and/or extends between a surface region 10 and the subterranean formation. Subterranean formation 22 is present within a subsurface region 20 and may include a hydrocarbon 24.

Hydrocarbon well 30 further includes a casing string 40 that extends within the wellbore 32 and defines a casing conduit 44. An autonomous perforation device 100 may be present within the casing conduit. Autonomous perforation device 100 includes a perforation assembly 110 and a motion-arresting assembly 130. In addition, autonomous perforation device 100 at least partially defines a fluid flow conduit 150. Fluid flow conduit 150 additionally or alternatively may be referred to herein as a fluid conduit 150.

Autonomous perforation device 100 may be configured to be located within casing conduit 44 and to flow, be flowed, and/or be conveyed with a carrier fluid stream 70 in a downhole direction 38. This may include flowing the autonomous perforation device to a target region 46 of the casing conduit. Subsequent to autonomous perforation device 100 reaching target region 46, and as discussed in more detail herein, motion-arresting assembly 130 may be selectively actuated to arrest, slow, and/or stop motion of the autonomous perforation device and/or to retain the autonomous perforation device within the target region of the casing conduit. This may include operatively engaging an inner wall 42 of casing string 40 with motion-arresting assembly 130 and/or receiving (or operatively engaging) motion-arresting assembly 130 on a projection 48 that may be present within (or that may define a reduced-area region of) casing conduit 44. Inner wall 42 additionally or alternatively may be referred to as interior surface 42, inner surface 42, and/or casing-conduit-defining surface 42 of the casing string 40.

Subsequently, a stimulant fluid stream 80 may be provided to casing conduit 44. The stimulant fluid stream may flow in downhole direction 38 through fluid flow conduit 150 of autonomous perforation device 100 and into subterranean formation 22 via one or more perforations 112 that may be downhole from the autonomous perforation device. Depending upon a composition, flow rate, and/or pressure of stimulant fluid stream 80, this may permit stimulation, fracturing, and/or propping of a portion of subterranean formation 22 and/or may generate one or more stimulated regions 26 within the subterranean formation. Stimulated regions 26 may be described as being proximate, near, and/or in fluid communication with the one or more perforations 112.

After flowing stimulant fluid through the one or more perforations 112, such as to form one or more stimulated regions 26, fluid flow through perforations 112 may be sealed, restricted, blocked, occluded, and/or stopped. This may be accomplished in any suitable manner. As an illustrative, non-exclusive example, one or more ball sealers 90 may be flowed through fluid conduit 150 to seal perforation(s) 112. As another illustrative, non-exclusive example, autonomous perforation device 100 further may include a fluid conduit sealing assembly 170, which may be actuated to restrict, block, occlude, and/or stop fluid flow through the fluid flow conduit. This may include receiving a ball sealer 90 on a ball sealer seat 174 that may be defined by autonomous perforation device 100 to seal, restrict, block, occlude, and/or stop fluid flow through fluid conduit 150. Fluid conduit sealing assembly 170 additionally or alternatively may be referred to herein as a fluid flow conduit sealing assembly 170.

As discussed in more detail herein, restriction of fluid flow through perforations 112 may be concurrent with supply of carrier fluid stream 70 and/or stimulant fluid stream 80 to casing conduit 44. As such, restriction of the fluid flow through the perforations may generate an increase in pressure within casing conduit 44, within target region 46, within a portion of casing conduit 44 that is proximal to autonomous perforation device 100, and/or within a portion of casing conduit 44 that is uphole (or in an uphole direction 36) from autonomous perforation device 100. As also discussed in more detail herein, perforation assembly 110 of autonomous perforation device 100 may be configured to autonomously generate one or more perforations within casing string 40 responsive to the pressure within the casing conduit and proximal to the autonomous perforation device (and/or a pressure sensor, pressure detector, and/or pressure-activated component thereof) exceeding a threshold perforating pressure.

Wellbore 32 may define any suitable shape, profile, configuration, and/or trajectory within subsurface region 20. As an illustrative, non-exclusive example, and as illustrated in solid lines in FIG. 1, wellbore 32 may include a vertical, or at least substantially vertical, portion. As another illustrative, non-exclusive example, and as indicated in dashed lines in FIG. 1, wellbore 32 also may include a deviated and/or horizontal portion.

In addition, autonomous perforation device 100 may be present at any suitable location within wellbore 32 and/or within casing conduit 44 that is defined therein. As an illustrative, non-exclusive example, and as indicated in dash-dot-dot lines in FIG. 1, autonomous perforation device 100 may be located within the deviated, or horizontal, portion of wellbore 32. As another illustrative, non-exclusive example, and as indicated in dash-dot lines in FIG. 1, autonomous perforation device 100 may be located within the vertical portion of wellbore 32. Although not required, use of autonomous perforation device 100 and/or the methods disclosed herein in a horizontal portion of wellbore 32 may be beneficial, as gravity is not able to convey an autonomous (or other) perforation device through such a horizontal portion.

Carrier fluid stream 70 may include and/or be any suitable fluid stream that may be utilized to convey autonomous perforation device 100 in downhole direction 38. As an illustrative, non-exclusive example, the carrier fluid stream may include and/or be a fracturing fluid stream that also may be utilized to fracture subterranean formation 22. In such an embodiment, the fracturing fluid stream may include proppant in addition to a fracturing fluid. As another illustrative, non-exclusive example, the carrier fluid stream may be (at least substantially) free of particulate material. As additional illustrative, non-exclusive examples, the carrier fluid stream may include and/or be a water stream, an aqueous stream, a liquid stream, a gas stream, and/or a foam stream.

Stimulant fluid stream 80 also may include and/or be any suitable fluid stream that may be utilized to stimulate subterranean formation 22, such as by flowing through fluid conduit 150 and into the subterranean formation via perforations 112. As an illustrative, non-exclusive example, the stimulant fluid stream may include particulate material. As additional illustrative, non-exclusive examples, the stimulant fluid stream may include and/or be a proppant stream, a proppant slurry stream, a liquid stream, a slurry stream, an acid stream, a foam stream, and/or a gas stream.

It is within the scope of the present disclosure that carrier fluid stream 70 may be (at least substantially) similar to stimulant fluid stream 80. Thus, the carrier fluid stream may be the stimulant fluid stream and/or may include a similar (or identical) chemical composition to a chemical composition of the stimulant fluid stream. Alternatively, it is also within the scope of the present disclosure that carrier fluid stream 70 may be (at least substantially) different from stimulant fluid stream 80. Thus, the carrier fluid stream may include a different chemical composition than the composition of the stimulant fluid stream and/or may be free (or at least substantially free) of proppant or other particulate that is present in the stimulant fluid stream.

Casing string 40 may include and/or be any suitable tubular structure that may be located, may extend, and/or may be placed within wellbore 32 to create and/or define casing conduit 44. As illustrative, non-exclusive examples, casing string 40 also may be referred to herein as and/or may be a wellbore casing 40, a tubing 40, and/or a liner 40. Similarly, casing conduit 44 also may be referred to herein as and/or may be a wellbore conduit 44, a tubing conduit 44, and/or a liner conduit 44.

FIG. 2 is a schematic representation of illustrative, non-exclusive examples of an autonomous perforation device 100 according to the present disclosure. Autonomous perforation device 100 of FIG. 2 may include and/or be autonomous perforation device 100 of FIG. 1. Any of the structures, components, and/or features that are discussed herein with reference to autonomous perforation device 100 of FIG. 2 may be included in and/or utilized with hydrocarbon well 30 and/or autonomous perforation device 100 of FIG. 1 without departing from the scope of the present disclosure.

Autonomous perforation device 100 includes a perforation assembly 110, which may be configured to create one or more perforations within a casing string, and a motion-arresting assembly 130, which may be selectively actuated to retain the autonomous perforation device within a target region of a casing conduit that is defined by the casing string. In addition, autonomous perforation device 100 at least partially defines at least one fluid flow conduit 150. Fluid flow conduit 150 is configured to permit fluid flow between an uphole portion 102 of the autonomous perforation device and a downhole portion 104 of the autonomous perforation device when the autonomous perforation device is retained within the casing conduit, such as within a target region thereof. Uphole portion 102 also may be referred to herein as an uphole side 102, an uphole region 102, an uphole area 102, and/or an uphole-facing portion 102 of the autonomous perforation device. Similarly, downhole portion 104 also may be referred to herein as a downhole side 104, a downhole region 104, a downhole area 104, and/or a downhole-facing portion 104 of the autonomous perforation device.

In addition, and as illustrated in dashed lines in FIG. 2, autonomous perforation device 100 also may include a fluid conduit sealing assembly 170, which may be configured to selectively restrict fluid flow through fluid conduit 150. The autonomous perforation device further may include an autonomous control assembly 180, which may be adapted, configured, designed, constructed, and/or programmed to control the operation of at least a portion of the autonomous perforation device. The autonomous perforation device also may include a storage structure 190 that may be configured to selectively release a sealing material 192.

Perforation assembly 110 may include and/or be any suitable structure that may be configured to be selectively actuated to create the one or more perforations within the casing string. As an illustrative, non-exclusive example, perforation assembly 110 may include and/or be a perforation gun 114 that includes one or more perforation charges 116. As another illustrative, non-exclusive example, perforation assembly 110 may include a firing mechanism 118 that may be configured to be selectively actuated to discharge the one or more perforation charges 116 and/or to create one or more perforations with the one or more perforation charges.

It is within the scope of the present disclosure that perforation assembly 110 may include and/or be an autonomous perforation assembly 110 that may be configured to autonomously discharge the one or more perforation charges and/or to create the one or more perforations 112 responsive to a wellbore pressure within the casing conduit proximal to the autonomous perforation assembly exceeding a threshold perforating pressure. Additionally or alternatively, it is also within the scope of the present disclosure that perforation assembly 110 may be configured to discharge the one or more perforation charges and/or create the one or more perforations 112 responsive to receipt of a perforation signal. Illustrative, non-exclusive examples of the perforation signal include any suitable wired perforation signal, wireless perforation signal, acoustic perforation signal, hydraulic perforation signal, and/or electromagnetic perforation signal.

Motion-arresting assembly 130 may include and/or be any suitable structure that may be adapted, configured, sized, and/or designed to selectively retain autonomous perforation device 100 within the target region of the casing conduit. As an illustrative, non-exclusive example, motion-arresting assembly 130 may define a retracted configuration 132 (as illustrated in solid lines in FIG. 2) and an expanded configuration 134 (as illustrated in dash-dot lines in FIG. 2). Motion-arresting assembly 130 may be configured to selectively transition from the retracted configuration to the expanded configuration to selectively retain the autonomous perforation device within the target region of the casing conduit.

As an illustrative, non-exclusive example, and when motion-arresting assembly 130 is in retracted configuration 132, the motion-arresting assembly may be sized to permit autonomous perforation device 100 to move, translate, and/or flow within casing conduit 44. For example, the autonomous perforation device may flow through the casing conduit with the carrier fluid stream. As another illustrative, non-exclusive example, and when motion-arresting assembly 130 is in expanded configuration 134, the motion-arresting assembly may be sized to restrict motion of autonomous perforation device 100 within casing conduit 44. As discussed, this restriction may be accomplished through operative engagement between motion-arresting assembly 130 and an inner wall of the casing string and/or through operative engagement between the motion-arresting assembly and a projection that extends into the casing string. As discussed in more detail herein, in the expanded configuration and when the fluid flow conduit(s) defined by and/or through the autonomous perforation device are not sealed, the carrier fluid stream and/or a stimulant fluid stream may flow past/through the autonomous perforation device.

Retracted configuration 132 may be a relative configuration and may define any suitable configuration in which motion-arresting assembly 130 is sized to permit the autonomous perforation device to translate within casing conduit 44 and/or to flow past the projection, when present. Similarly, expanded configuration 134 may be a relative configuration and may define any suitable configuration in which motion-arresting assembly 130 is not sized to permit the autonomous perforation device to translate within casing conduit 44, is not sized to permit the autonomous perforation device to flow past the projection, when present, and/or is sized to retain the autonomous perforation device within the target region of the casing conduit.

As an illustrative, non-exclusive example, motion-arresting assembly 130 may define a retracted cross-sectional area when in retracted configuration 132. The motion-arresting assembly also may define an expanded cross-sectional area when in expanded configuration 134. The retracted cross-sectional area may be less than the expanded cross-sectional area and both may be defined in a direction that is transverse to a length of the casing conduit when the autonomous perforation device is present within the casing conduit. As illustrative, non-exclusive examples, the retracted cross-sectional area may be less than 95%, less than 90%, less than 80%, less than 70%, less than 60%, or less than 50% of the expanded cross-sectional area. Additionally or alternatively, the retracted cross-sectional area also may be at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, or at least 70% of the expanded cross-sectional area.

As another illustrative, non-exclusive example, the retracted cross-sectional area may be less than a cross-sectional area of the casing conduit (or a cross-sectional area of the target region of the casing conduit). As illustrative, non-exclusive examples, the retracted cross-sectional area may be less than 95%, less than 90%, less than 80%, less than 70%, less than 60%, or less than 50% of the cross-sectional area of the casing conduit. As yet another illustrative, non-exclusive example, the expanded cross-sectional area may be at least a threshold fraction of the cross-sectional area of the casing conduit. As illustrative, non-exclusive examples, the expanded cross-sectional area may be at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% of the cross-sectional area of the casing conduit.

As another illustrative, non-exclusive example, motion-arresting assembly 130 may define a retracted maximum dimension when in retracted configuration 132 and an expanded maximum dimension when in expanded configuration 134. The retracted maximum dimension may be less than the expanded maximum dimension and both may be defined in the direction that is transverse to the length of the casing conduit when the autonomous perforation device is present within the casing conduit. As illustrative, non-exclusive examples, the retracted maximum dimension may be less than 95%, less than 90%, less than 80%, less than 70%, less than 60%, or less than 50% of the expanded maximum dimension. Additionally or alternatively, the retracted maximum dimension also may be at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, or at least 70% of the expanded maximum dimension.

As another illustrative, non-exclusive example, the retracted maximum dimension may be less than a maximum cross-sectional dimension of the casing conduit (or a maximum cross-sectional dimension of the target region of the casing conduit). As illustrative, non-exclusive examples, the retracted maximum dimension may be less than 95%, less than 90%, less than 80%, less than 70%, less than 60%, or less than 50% of the maximum cross-sectional dimension of the casing conduit. As yet another illustrative, non-exclusive example, the expanded maximum dimension may be at least a threshold fraction of the maximum cross-sectional dimension of the casing conduit. As illustrative, non-exclusive examples, the expanded maximum cross-sectional dimension may be at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% of the maximum cross-sectional dimension of the casing conduit.

It is within the scope of the present disclosure that motion-arresting assembly 130 may transition between the retracted configuration and the expanded configuration in any suitable manner and/or utilizing any suitable structure. As an illustrative, non-exclusive example, and as discussed in more detail herein, motion-arresting assembly 130 may include a plurality of fins 152, and the motion-arresting assembly may extend the fins to transition from the retracted configuration to the expanded configuration. Fins 152 additionally or alternatively may be referred to as projections 152, casing-engaging structures 152, and/or extensions 152.

It is within the scope of the present disclosure that motion-arresting assembly 130 may include and/or be an autonomous motion-arresting assembly 130 that may be configured to autonomously retain the autonomous perforation device within the target region of the casing conduit responsive to, or responsive to satisfaction of, a retention criterion. Illustrative, non-exclusive examples of the retention criterion include a pressure within the casing conduit proximal to the autonomous perforation device exceeding a threshold retention pressure, the autonomous perforation device being present within the target region of the casing conduit, the autonomous perforation device flowing along a target length of the casing conduit, and/or the autonomous perforation device flowing through, or past, a target number of casing collars of the casing string.

Additionally or alternatively, it is also within the scope of the present disclosure that motion-arresting assembly 130 may be configured to retain the autonomous perforation device within the target region of the casing conduit responsive to receipt of a retention signal. Illustrative, non-exclusive examples of the retention signal include any suitable wired retention signal, wireless retention signal, acoustic retention signal, hydraulic retention signal, and/or electromagnetic retention signal.

Fluid flow conduit 150 may define any suitable shape that permits the fluid flow between uphole portion 102 and downhole portion 104 of autonomous perforation device 100 when, or while, the autonomous perforation device is retained within the target region of the casing conduit. As an illustrative, non-exclusive example, the fluid flow conduit may be (at least substantially) cylindrical (or have an at least substantially circular cross-sectional shape). As another illustrative, non-exclusive example, the fluid flow conduit may define at least a portion (or a sector) of an annular region that extends between the autonomous perforation device and the casing string when the autonomous perforation device is present within the casing conduit. Uphole side 102 and downside hole 104 additionally or alternatively may be referred to as the uphole-facing surface 102 and downhole-facing surface 104 and/or as the uphole portion 102 and downhole portion 104 of autonomous perforation device 110.

A cross-sectional area and/or shape of fluid flow conduit 150 may be selected and/or sized based upon any suitable criteria. As an illustrative, non-exclusive example, the cross-sectional area and/or shape of the fluid flow conduit may be selected to provide less than a threshold pressure drop across the autonomous perforation device when the autonomous perforation device is retained within the target region of the casing conduit and the stimulant fluid stream is flowing therepast. As another illustrative, non-exclusive example, and as discussed, the cross-sectional area and/or shape may be selected to permit a ball sealer to pass through the fluid flow conduit and/or between uphole portion 102 and downhole portion 104 of autonomous perforation device 100.

It is within the scope of the present disclosure that autonomous perforation device 100 may at least partially define any suitable number of fluid flow conduits 150 and/or that the fluid flow conduits may be defined by any suitable structure. As illustrative, non-exclusive examples, the autonomous perforation device may define at least 1, at least 2, at least 3, at least 4, at least 5, or at least 6 fluid flow conduits 150. As another illustrative, non-exclusive example, and when motion-arresting assembly 130 includes the plurality of fins 152, the plurality of fins may at least partially define the plurality of fluid flow conduits. Additionally or alternatively, the plurality of fluid flow conduits 150 also may be at least partially defined by the inner surface of the casing string when the autonomous perforation device is located within the casing conduit.

Fluid conduit sealing assembly 170 may include any suitable structure that may be configured to selectively restrict fluid flow through fluid conduit 150. As an illustrative, non-exclusive example, fluid conduit sealing assembly 170 may include and/or be a valve 172 that is configured to selectively transition between an open configuration and a closed configuration. In the open configuration, the valve may permit the fluid flow through the fluid flow conduit. In the closed configuration, the valve may restrict, limit, occlude, and/or block the fluid flow through the fluid flow conduit.

When fluid conduit sealing assembly 170 includes valve 172, the valve may include and/or be an autonomous valve 172 that may be configured to autonomously transition between the open configuration and the closed configuration responsive to any suitable criteria. As an illustrative, non-exclusive example, valve 172 may transition between the open configuration and the closed configuration responsive to the motion-arresting assembly retaining the autonomous perforation device within the target region of the casing conduit for at least a threshold retention time.

Additionally or alternatively, valve 172 may be configured to transition between the open configuration and the closed configuration responsive to receipt of a valve transition signal. Illustrative, non-exclusive examples of valve transition signals include any suitable wired valve transition signal, wireless valve transition signal, acoustic valve transition signal, hydraulic valve transition signal, and/or electromagnetic valve transition signal.

As another illustrative, non-exclusive example, fluid conduit sealing assembly 170 may include and/or be a ball sealer seat 174 that may be at least partially defined by the autonomous perforation device. Ball sealer seat 174 may be configured to selectively restrict the fluid flow through fluid flow conduit 150 responsive to receipt of a ball sealer (such as ball sealer 90 of FIG. 1) thereon.

It is within the scope of the present disclosure that autonomous perforation device 100 may include and/or be a frangible autonomous perforation device 100 that may be configured to disintegrate, break apart, crumble, and/or be destroyed upon, or subsequent to, discharge of the one or more perforation charges and/or creation of the one or more perforations. It is also within the scope of the present disclosure that, upon breaking apart, autonomous perforation device 100 may define sealing material 192. As an illustrative, non-exclusive example, a material of construction of such a frangible autonomous perforation device may be selected such that the frangible autonomous perforation device breaks apart to form, or define, the sealing material.

Additionally or alternatively, and as discussed, autonomous perforation device 100 may include a separate, or dedicated, storage structure 190 that contains sealing material 192 and that is configured to selectively release the sealing material. Illustrative, non-exclusive examples of sealing material 192 include any suitable ball sealer, particulate material, and/or supplemental sealing material that is configured to supplement sealing by the ball sealer.

Autonomous control assembly 180 may include any suitable structure that may be configured to control the operation of at least the portion of the autonomous perforation device. As illustrative, non-exclusive examples, the autonomous control assembly may be configured to actuate perforation assembly 110, actuate the motion-arresting assembly 130, and/or selectively restrict the fluid flow through fluid flow conduit 150, such as via fluid conduit sealing assembly 170.

It is within the scope of the present disclosure that autonomous control assembly 180 may include and/or be a mechanical autonomous control assembly 182. As an illustrative, non-exclusive example, the autonomous control assembly may include a (mechanical) pressure actuator that is configured to actuate responsive to a pressure in the casing conduit proximal to the autonomous perforation device exceeding a threshold actuation pressure. Additionally or alternatively, it is also within the scope of the present disclosure that autonomous control assembly 180 may include an electronic controller 184 that is programmed to control the operation of the portion of the autonomous perforation device.

When autonomous control assembly 180 includes electronic controller 184, the electronic controller may be programmed to control the operation of autonomous perforation device 100 in any suitable manner. As an illustrative, non-exclusive example, electronic controller 184 may include and/or execute one or more algorithms. The one or more algorithms may be executed to control the actuation and/or operation of any suitable portion of autonomous perforation device 100, such as perforation assembly 110, motion-arresting assembly 130, and/or fluid conduit sealing assembly 170, when present. This may include autonomous and/or independent control of autonomous perforation device 100, such as when electronic controller 184 is programmed to control the operation of the portion of the autonomous perforation device without, or independent from, receipt of a signal.

Additionally or alternatively, electronic controller 184 may be programmed to control the operation of the portion of the autonomous perforation device by generating and/or responsive to receipt of one or more signals. Illustrative, non-exclusive examples of these signals include any suitable perforation signal, retention signal, and/or valve transition signal and are discussed in more detail herein.

When electronic controller 184 receives the signals, the electronic controller further may include and/or be any suitable signal-receiving structure. Additionally or alternatively, and when electronic controller 184 generates the signals, the electronic controller further may include and/or be any suitable signal-generation structure. It is within the scope of the present disclosure that electronic controller 184 may receive the signals from an external signal source. This may include any suitable external signal source that may be associated with hydrocarbon well 30, that may be located within wellbore 32, and/or that may be located within surface region 10.

FIGS. 3-6 are less schematic but still illustrative, non-exclusive examples of an autonomous perforation device 100 according to the present disclosure. The autonomous perforation device of FIGS. 3-6 includes a perforation assembly 110 and a motion-arresting assembly 130 in the form of a plurality of fins 152. Fins 152 are configured to transition between a contracted configuration 132 (as illustrated in the schematic side view of FIG. 3 and in the schematic end view of FIG. 4) and an expanded configuration 134 (as illustrated in the schematic side view of FIG. 5 and in the schematic end view of FIG. 6).

When fins 152 are in contracted configuration 132, autonomous perforation device 100 may be sized to translate, move, and/or flow within a casing conduit 44 that is defined by a casing string 40. However, and when fins 152 are in expanded configuration 134, the fins may operatively engage with an inner wall 42 of the casing string and/or with a projection 48 that extends from the inner surface of the casing string (as discussed in more detail herein). This may restrict motion of the autonomous perforation device within the casing conduit. In addition, motion-arresting assembly 130 and inner wall 42 together may define a plurality of fluid flow conduits 150. The fluid flow conduits may be sized to permit a fluid and/or a ball sealer to flow therethrough while motion-arresting assembly 130 is located within casing conduit 44 and in expanded configuration 134.

FIGS. 7-10 are less schematic but still illustrative, non-exclusive examples of another autonomous perforation device 100 according to the present disclosure. The autonomous perforation device of FIGS. 7-10 may be at least substantially similar to the autonomous perforation device of FIGS. 3-6 and may include a motion-arresting assembly 130 that may be configured to transition between a retracted configuration 132 (as illustrated in the schematic side view of FIG. 7 and in the schematic end view of FIG. 8) and an expanded configuration 134 (as illustrated in the schematic side view of FIG. 9 and in the schematic end view of FIG. 10). However, and as illustrated in FIGS. 7-10, motion-arresting assembly 130 may include a plurality of fins 152 shaped to define a plurality of fluid flow conduits 150 and also to define a plurality of ball sealer seats 174 when the fins are in the expanded configuration.

Fluid flow conduits 150 may be sized to permit fluid to flow therethrough when motion-arresting assembly 130 is in expanded configuration 134. In addition, ball sealer seats 174 may be sized to receive a ball sealer and to restrict fluid flow through a corresponding fluid flow conduit when the ball sealer is received on the ball sealer seat.

FIGS. 11-19 are schematic representations of illustrative, non-exclusive examples of process flows that may utilize a hydrocarbon well 30, an autonomous perforation device 100, and/or a method according to the present disclosure. In FIG. 11, an autonomous perforation device 100 is present within a casing conduit 44 that is defined by a casing string 40 and is flowing in a downhole direction 38 with, or within, a carrier fluid stream 70. The carrier fluid stream may be provided to the casing conduit and may flow through the casing conduit and into a subterranean formation 22 via one or more perforations 112 that may be present within the casing string. In addition, a motion-arresting assembly 130 of the autonomous perforation device is in a retracted configuration 132, thereby permitting motion of the autonomous perforation device within the casing conduit.

When autonomous perforation device 100 reaches a target region 46 of casing conduit 44, and as illustrated in FIG. 12, motion-arresting assembly 130 may transition to an expanded configuration 134, thereby retaining autonomous perforation device 100 within the target region of the casing conduit. This may include operatively engaging motion-arresting assembly 130 with an inner wall 42 of casing string 40 and/or with a projection 48 that extends within casing conduit 44, as discussed in more detail herein.

As also illustrated in FIG. 12, autonomous perforation device 100 and/or motion-arresting assembly 130 thereof at least partially defines one or more fluid flow conduits 150. Thus, and as illustrated in FIG. 13, a stimulant fluid stream 80 may be provided to casing conduit 44. The stimulant fluid stream may flow through fluid flow conduits 150 and into subterranean formation 22 via perforations 112, thereby stimulating the subterranean formation and/or creating a stimulated region 26 within the subterranean formation. As an illustrative, non-exclusive example, and as illustrated in dashed lines in FIG. 13, the stimulant fluid stream may include and/or be a proppant slurry stream 82.

When stimulant fluid stream 80 includes proppant slurry stream 82, and as illustrated in FIG. 14, the proppant slurry stream sometimes may block, restrict, and/or occlude fluid flow through perforations 112 that are downhole from autonomous perforation device 100, producing what may be referred to as a screenout event 84. The screenout event may include the collection, agglomeration, and/or accumulation of particulate material within casing conduit 44 and may complicate further wellbore completion operations within hydrocarbon well 30.

However, continued supply of stimulant fluid stream 80 to the casing conduit concurrent with the presence of the screenout event within the casing conduit may generate a pressure increase within the casing conduit. Under these conditions, and when the pressure within the casing conduit and proximal to autonomous perforation device 100 exceeds a threshold screenout pressure, the autonomous perforation device may be configured to create one or more new perforations 112 within the casing conduit. These new perforations may be uphole from screenout event 84 and may permit proppant slurry stream 82 to flow therethrough and into the subterranean formation, thereby decreasing further accumulation of particulate material within the casing conduit and decreasing a severity of the screenout event.

Additionally or alternatively, supply of the proppant slurry stream to the casing conduit may not produce a screenout event and/or may not produce a pressure within the casing conduit that is sufficient to cause autonomous perforation device 100 to create the new perforations. Under these conditions, and subsequent to creation of stimulated regions 26 and/or supply of sufficient stimulant fluid stream 80 to stimulated regions 26, a fluid flow through perforations 112 and/or through fluid flow conduits 150 may be blocked, restricted, and/or otherwise occluded.

As illustrated in FIG. 15, the fluid flow through perforation(s) 112 may be blocked in any suitable manner. As an illustrative, non-exclusive example, and as illustrated in dashed lines in FIG. 15, one or more ball sealers 90 may be flowed through fluid flow conduits 150 and seated upon perforations 112, thereby restricting fluid flow through the perforations. As another illustrative, non-exclusive example, and as also illustrated in dashed lines in FIG. 15, autonomous perforation device 100 may include a fluid conduit sealing assembly 170 in the form of a ball sealer seat 174, and one or more ball sealers 90 may be seated on ball sealer seats 174, thereby restricting fluid flow through fluid flow conduits 150, at least in downhole direction 38. As yet another illustrative, non-exclusive example, a valve 172 that may be associated with fluid conduit sealing assembly 170 may be closed, thereby restricting fluid flow through fluid flow conduits 150.

In addition, carrier fluid stream 70 again may be supplied to the casing conduit. Supply of the carrier fluid stream to the casing conduit, together with restriction of fluid flow out of the casing conduit via perforations 112 may increase a pressure within the casing conduit. As illustrated in FIG. 16, and responsive to the pressure within the casing conduit exceeding a threshold perforating pressure, autonomous perforation device 100 may generate one or more new (or uphole) perforations 112 within the casing conduit. This may permit carrier fluid stream 70 to flow from casing conduit 44 into subterranean formation 22 via the new perforations, which may stimulate and/or fracture the subterranean formation. Concurrently, and as also illustrated in FIG. 16, a second autonomous perforation device 100 may be flowed into the casing conduit with, or within, the carrier fluid stream.

When the second autonomous perforation device reaches a (second) target, or desired, region 46 within casing conduit 44, and as illustrated in FIG. 17, a motion-arresting assembly 130 associated therewith may transition to an expanded configuration 134, thereby retaining the second autonomous perforation device within the target region of the casing conduit. In addition, stimulant fluid stream 80 again may be provided to the casing conduit. The stimulant fluid stream may flow through fluid flow conduits 150 of the second autonomous perforation device and into subterranean formation 22 via new perforations 112 to stimulate the subterranean formation.

In addition, and as illustrated in dashed lines in FIG. 17 and discussed in more detail herein, the autonomous perforation device that was utilized to create new perforations 112 may break apart, as indicated at 106. Thus, and subsequent to completion and/or stimulation of hydrocarbon wells 30 with autonomous perforation devices 100 according to the present disclosure, it may not be necessary to remove the autonomous perforation devices from the casing conduit, it may not be necessary to drill the autonomous perforation devices from the casing conduit, and/or broken-apart autonomous perforation devices 106 may be flowed from the casing conduit during production from the subterranean formation.

Subsequent to creation of a stimulated region 26 proximal to new perforations 112, and as illustrated in FIG. 18, flow through the new perforations and into the subterranean formation may be blocked, restricted, and/or occluded. This may be at least substantially similar to the fluid flow restriction that is discussed herein with reference to FIG. 15 and may be accomplished using any suitable ball sealer 90 and/or fluid conduit sealing assembly 170.

Concurrent with the flow blockage, carrier fluid stream 70 may be provided to casing conduit 44. This may pressurize the casing conduit, causing the autonomous perforation device to create one or more additional perforations 112 responsive to the pressure within the casing conduit exceeding the threshold perforation pressure.

This process may be repeated any suitable number of times to create any suitable number of perforations within the casing string and/or to stimulate any suitable number of regions of the subterranean formation.

FIG. 20 is a flowchart depicting methods 200 according to the present disclosure of stimulating a subterranean formation. Methods 200 may include providing a carrier fluid stream to a casing conduit at 205 and/or locating an autonomous perforation device within the casing conduit at 210. Methods 200 include flowing an autonomous perforation device within the casing conduit at 215 and retaining the autonomous perforation device within a target region of the casing conduit at 220. Methods 200 may include providing a stimulant fluid stream to the casing conduit at 225 and/or ceasing the providing the carrier fluid stream to the casing conduit at 230. Methods 200 further include flowing the stimulant fluid stream within the casing conduit at 235 and stimulating a portion of a subterranean formation at 240. Methods 200 also may include ceasing the providing the stimulant fluid stream to the casing conduit at 245, fluidly isolating a target region of the casing conduit from the subterranean formation at 250, perforating a casing string that defines the casing conduit at 255, releasing a sealing material at 260, and/or repeating at least a portion of the methods at 265.

Providing the carrier fluid stream to the casing conduit at 205 may include providing any suitable carrier fluid stream to the casing conduit in any suitable manner. As an illustrative, non-exclusive example, the providing at 205 may include pumping the carrier fluid stream into the casing conduit. As another illustrative, non-exclusive example, the providing at 205 also may include providing the carrier fluid stream from a surface region and into the casing conduit. Although not required, the carrier fluid stream may have a (substantially) different composition than a composition of the stimulant fluid stream or may be (at least substantially) similar to the stimulant fluid stream. Illustrative, non-exclusive examples of the carrier fluid stream are discussed herein.

Locating the autonomous perforation device within the casing conduit at 210 may include locating the autonomous perforation device in any suitable manner. As an illustrative, non-exclusive example, the locating at 210 may include placing the autonomous perforation device within the casing conduit. As another illustrative, non-exclusive example, the locating at 210 may include transferring the autonomous perforation device from a surface region into the casing conduit. As yet another illustrative, non-exclusive example, the locating at 210 may include lubricating the autonomous perforation device into the casing conduit.

It is within the scope of the present disclosure that the locating at 210 may be performed at any suitable time during methods 200. As illustrative, non-exclusive examples, the locating at 210 may be performed prior to the flowing at 215, prior to the retaining at 220, prior to the providing at 225, prior to the ceasing at 230, prior to the flowing at 235, prior to the stimulating at 240, prior to the ceasing at 245, prior to the fluidly isolating at 250, prior to the perforating at 255, and/or prior to the releasing at 260.

Flowing the autonomous perforation device within the casing conduit at 215 may include flowing the autonomous perforation device in any suitable manner. As an illustrative, non-exclusive example, the flowing at 215 may include flowing the autonomous perforation device with, or within, the carrier fluid stream. As another illustrative, non-exclusive example, the flowing at 215 also may include conveying and/or translating the autonomous perforation device along at least a portion of a length of the casing conduit. As yet another illustrative, non-exclusive example, the flowing at 215 may include flowing the autonomous perforation device from, or from near, the surface region and/or to, or into, the target region of the casing conduit.

Retaining the autonomous perforation device within the target region of the casing conduit at 220 may include retaining the autonomous perforation device in any suitable manner. As an illustrative, non-exclusive example, the retaining at 220 may include (at least substantially) ceasing motion of the autonomous perforation device within the casing conduit. As another illustrative, non-exclusive example, the retaining at 220 also may include expanding the autonomous perforation device and/or transitioning the autonomous perforation device from a retracted configuration to an expanded configuration to retain the autonomous perforation device within the target region of the casing conduit.

As yet another illustrative, non-exclusive example, the retaining at 220 may include retaining with a motion-arresting assembly that forms a portion of the autonomous perforation device. Illustrative, non-exclusive examples of the motion-arresting assembly are disclosed herein. Under these conditions, the retaining at 220 also may include actuating the motion-arresting assembly, operatively engaging at least a portion of the motion-arresting assembly with a projection that extends within the casing conduit, and/or operatively engaging at least a portion of the motion-arresting assembly with the casing string (or an inner wall of the casing string).

It is within the scope of the present disclosure that the retaining at 220 may be performed at any suitable time and/or with any suitable sequence within methods 200. As illustrative, non-exclusive examples, the retaining at 220 may be performed subsequent to the providing at 205, subsequent to the locating at 210, and/or subsequent to the flowing at 215. As additional illustrative, non-exclusive examples, the retaining at 220 also may be performed prior to the providing at 225, at least partially concurrently with the providing at 225, prior to the ceasing at 230, prior to the flowing at 235, prior to the stimulating at 240, prior to the ceasing at 245, prior to the fluidly isolating at 250, prior to the perforating at 255, and/or prior to the releasing at 260.

Providing the stimulant fluid stream to the casing conduit at 225 may include providing any suitable stimulant fluid stream to the casing conduit in any suitable manner. As an illustrative, non-exclusive example, the providing at 225 may include pumping the stimulant fluid stream into the casing conduit. As another illustrative, non-exclusive example, the providing at 225 also may include providing the stimulant fluid stream from a surface region and into the casing conduit. Although not required, the stimulant fluid stream may have a (substantially) different composition than a composition of the carrier fluid stream or may be (at least substantially) similar to the carrier fluid stream. Illustrative, non-exclusive examples of the stimulant fluid stream are discussed herein.

Ceasing the providing the carrier fluid stream to the casing conduit at 230 may include ceasing supply of the carrier fluid stream to the casing conduit and/or ceasing a flow of the carrier fluid stream to the casing conduit. As an illustrative, non-exclusive example, and when the carrier fluid stream is different from the stimulant fluid stream, the ceasing at 230 may include ceasing the providing the carrier fluid stream during at least a portion of the providing the stimulant fluid stream at 225. Under these conditions, and subsequent to the stimulating at 240 and/or subsequent to the ceasing at 245, methods 200 further may include resuming the providing at 205.

Flowing the stimulant fluid stream within the casing conduit at 235 may include flowing the stimulant fluid stream past the autonomous perforation device within the casing conduit. As an illustrative, non-exclusive example, the flowing at 235 may include flowing the stimulant fluid stream through a fluid flow conduit that is at least partially defined by the autonomous perforation device. As another illustrative, non-exclusive example, the flowing at 235 may include flowing the stimulant fluid stream along at least a portion of the length of the casing conduit. As yet another illustrative, non-exclusive example, the flowing at 235 may include flowing the stimulant fluid stream from the casing conduit into the subterranean formation via a perforation that is downhole from the autonomous perforation device.

Stimulating the portion of a subterranean formation at 240 may include stimulating a portion of the subterranean formation that is downhole from the autonomous perforation device. Additionally or alternatively, the stimulating at 240 may include stimulating the portion of the subterranean formation with the stimulant fluid stream and/or with the carrier fluid stream. This may include flowing the stimulant fluid stream and/or the carrier fluid stream from the casing conduit into the subterranean formation via the perforation that is downhole from the autonomous perforation device, as discussed.

It is within the scope of the present disclosure that the stimulating at 240 may include stimulating the subterranean formation in any suitable manner. As illustrative, non-exclusive examples, the stimulating at 240 may include fracturing the portion of the subterranean formation, propping one or more fractures within the portion of the subterranean formation, and/or acid treating the portion of the subterranean formation.

Ceasing the providing the stimulant fluid stream to the casing conduit at 245 may include ceasing supply of the stimulant fluid stream to the casing conduit and/or ceasing a flow of the stimulant fluid stream to the casing conduit. As an illustrative, non-exclusive example, and when the stimulant fluid stream is different from the carrier fluid stream, the ceasing at 245 may include ceasing the providing the stimulant fluid stream during at least a portion of the providing the carrier fluid stream at 205 and/or during at least a portion of the resuming the providing at 205. As another illustrative, non-exclusive example, the ceasing at 245 may include ceasing subsequent to at least a portion of the stimulating at 240.

Fluidly isolating a target region of the casing conduit from the subterranean formation at 250 may include fluidly isolating the target region in any suitable manner. As an illustrative, non-exclusive example, the fluidly isolating at 250 may include locating a ball sealer on a ball sealer seat that is defined by the autonomous perforation device. This may restrict fluid flow through the fluid flow conduit, past the autonomous perforation device, and/or from a region of the casing conduit that is uphole from the autonomous perforation device to a region of the casing conduit that is downhole from the autonomous perforation device. As another illustrative, non-exclusive example, the fluidly isolating at 250 also may include closing a valve that forms a portion of the autonomous perforation device. This may restrict fluid flow through the fluid flow conduit, past the autonomous perforation device, and/or from a region of the casing conduit that is uphole from the autonomous perforation device to a region of the casing conduit that is downhole from the autonomous perforation device. As yet another illustrative, non-exclusive example, the fluidly isolating at 250 also may include flowing a ball sealer through the fluid flow conduit and locating the ball sealer on the perforation (or an existing perforation) that is downhole from the autonomous perforation device.

Perforating the casing string that defines the casing conduit at 255 may include perforating the casing string with the autonomous perforation device in any suitable manner and/or responsive to any suitable criteria. As an illustrative, non-exclusive example, the autonomous perforation device may include a perforation assembly, and the perforating at 255 may include perforating with the perforation assembly. Illustrative, non-exclusive examples of the perforation assembly are discussed herein.

As discussed, the stimulant fluid stream may include a proppant slurry stream that may, under certain conditions, produce a screenout event within the casing conduit. Under these conditions, the perforating at 255 may include perforating responsive to a pressure within the target region of the casing conduit exceeding a threshold screenout pressure.

Additionally or alternatively, and when methods 200 include the fluidly isolating at 250, the providing at 205 and/or the providing at 225 may be performed at least partially subsequent to the fluidly isolating at 250. This may increase a pressure within the casing conduit, as discussed herein, and the perforating at 255 may include perforating responsive to the pressure within the target region of the casing conduit exceeding a threshold perforating pressure, such as to permit flow of the carrier fluid stream and/or the stimulant fluid stream into the subterranean formation and/or to permit stimulation of a portion of the subterranean formation.

As discussed herein, the autonomous perforation device may include and/or be a frangible autonomous perforation device. Under these conditions, the perforating at 255 further may include breaking apart, destroying, crumbling, and/or disintegrating the frangible autonomous perforation device to generate a broken-apart autonomous perforation device. As also discussed, the broken-apart autonomous perforation device may include and/or be a sealing material and may contribute to the releasing at 260.

Releasing the sealing material at 260 may include releasing any suitable sealing material in any suitable manner. As an illustrative, non-exclusive example, the releasing at 260 may include releasing a ball sealer from the autonomous perforation device and/or from a storage structure that forms a portion of the autonomous perforation device. As another illustrative, non-exclusive example, the releasing at 260 also may include releasing a supplemental sealing material from the autonomous perforation device and/or from a storage structure that forms a portion of the autonomous perforation device. As yet another illustrative, non-exclusive example, the releasing at 260 may include breaking apart the autonomous perforation device, as discussed herein with reference to the perforating at 255.

Repeating at least a portion of the methods at 265 may include repeating any suitable portion of methods 200. Although not required, this may include repeating all, or substantially all, of methods 200. As an illustrative, non-exclusive example, the autonomous perforation device may be a first autonomous perforation device that is retained within a first target region of the casing conduit, and the repeating at 265 may include repeating the flowing at 215 to flow a second autonomous perforation device into the casing conduit, repeating the retaining at 220 to retain the second autonomous perforation device within a second target region of the casing conduit that is uphole from the first target region of the casing conduit, repeating the flowing at 235 to flow the stimulant fluid past the second autonomous perforation device, and/or repeating the stimulating at 240 to stimulate a second portion of the subterranean formation that is downhole from the second autonomous perforation device.

The repeating at 265 also may include repeating the perforating at 255. For example, the repeating may include perforating with the second autonomous perforation device responsive to occurrence of a screenout event within the casing conduit and/or responsive to a pressure within the second target region of the casing conduit exceeding the threshold screenout pressure. Additionally or alternatively, the repeating also may include repeating the fluidly isolating at 250 to fluidly isolate the second target region of the casing conduit from the subterranean formation while continuing the providing at 205, the providing at 225, and/or the flowing at 235. Furthermore, the repeating may include perforating with the second autonomous perforation device responsive to the pressure within the second target region of the casing conduit exceeding the threshold perforating pressure.

Subsequent to the repeating the perforating at 255, the repeating at 265 further may include repeating the flowing the carrier fluid and/or the stimulant fluid into the subterranean formation via a perforation that was created during the repeating the perforating at 255. This may fracture and/or stimulate another portion of the subterranean formation.

In the present disclosure, several of the illustrative, non-exclusive examples have been discussed and/or presented in the context of flow diagrams, or flow charts, in which the methods are shown and described as a series of blocks, or steps. Unless specifically set forth in the accompanying description, it is within the scope of the present disclosure that the order of the blocks may vary from the illustrated order in the flow diagram, including two or more of the blocks (or steps) occurring in a different order and/or concurrently. It is also within the scope of the present disclosure that the blocks, or steps, may be implemented as logic, which also may be described as implementing the blocks, or steps, as logics. In some applications, the blocks, or steps, may represent expressions and/or actions to be performed by functionally equivalent circuits or other logic devices. The illustrated blocks may, but are not required to, represent executable instructions that cause a computer, processor, and/or other logic device to respond, to perform an action, to change states, to generate an output or display, and/or to make decisions.

As used herein, the term “and/or” placed between a first entity and a second entity means one of (1) the first entity, (2) the second entity, and (3) the first entity and the second entity. Multiple entities listed with “and/or” should be construed in the same manner, i.e., “one or more” of the entities so conjoined. Other entities may optionally be present other than the entities specifically identified by the “and/or” clause, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising” may refer, in one embodiment, to A only (optionally including entities other than B); in another embodiment, to B only (optionally including entities other than A); in yet another embodiment, to both A and B (optionally including other entities). These entities may refer to elements, actions, structures, steps, operations, values, and the like.

As used herein, the phrase “at least one,” in reference to a list of one or more entities should be understood to mean at least one entity selected from any one or more of the entity in the list of entities, but not necessarily including at least one of each and every entity specifically listed within the list of entities and not excluding any combinations of entities in the list of entities. This definition also allows that entities may optionally be present other than the entities specifically identified within the list of entities to which the phrase “at least one” refers, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) may refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including entities other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including entities other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other entities). In other words, the phrases “at least one,” “one or more,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B, and/or C” may mean A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B and C together, and optionally any of the above in combination with at least one other entity.

In the event that any patents, patent applications, or other references are incorporated by reference herein and (1) define a term in a manner that is inconsistent with and/or (2) are otherwise inconsistent with, either the non-incorporated portion of the present disclosure or any of the other incorporated references, the non-incorporated portion of the present disclosure shall control, and the term or incorporated disclosure therein shall only control with respect to the reference in which the term is defined and/or the incorporated disclosure was present originally.

As used herein the terms “adapted” and “configured” mean that the element, component, or other subject matter is designed and/or intended to perform a given function. Thus, the use of the terms “adapted” and “configured” should not be construed to mean that a given element, component, or other subject matter is simply “capable of” performing a given function but that the element, component, and/or other subject matter is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the function. It is also within the scope of the present disclosure that elements, components, and/or other recited subject matter that is recited as being adapted to perform a particular function may additionally or alternatively be described as being configured to perform that function, and vice versa.

INDUSTRIAL APPLICABILITY

The systems and methods disclosed herein are applicable to the oil and gas industries.

It is believed that the disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed herein. Similarly, where the claims recite “a” or “a first” element or the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.

It is believed that the following claims particularly point out certain combinations and subcombinations that are directed to one of the disclosed inventions and are novel and non-obvious. Inventions embodied in other combinations and subcombinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower, or equal in scope to the original claims, are also regarded as included within the subject matter of the inventions of the present disclosure. 

1. A method of stimulating a subterranean formation, the method comprising: flowing, with a carrier fluid stream, an autonomous perforation device within a casing conduit that is defined by a casing string within the subterranean formation; retaining the autonomous perforation device within a target region of the casing conduit; subsequent to the retaining, flowing a stimulant fluid stream within the casing conduit and past the autonomous perforation device via a fluid flow conduit that is at least partially defined by the autonomous perforation device; and stimulating, with the stimulant fluid stream, a portion of the subterranean formation that is downhole from the autonomous perforation device.
 2. The method of claim 1, wherein the stimulant fluid stream is a proppant slurry stream, and further wherein the method includes perforating the casing string with the autonomous perforation device responsive to a pressure within the target region of the casing conduit exceeding a threshold screenout pressure.
 3. The method of claim 1, wherein the method further includes: fluidly isolating the target region of the casing conduit from the subterranean formation; and perforating the casing string responsive to a pressure within the target region of the casing conduit exceeding a threshold perforating pressure, wherein the perforating includes creating a perforation within the casing string with the autonomous perforation device.
 4. The method of claim 3, wherein the fluidly isolating includes at least one of: (i) locating a ball sealer on a ball sealer seat that is defined by the autonomous perforation device to restrict flow of the stimulant fluid stream past the autonomous perforation device; (ii) flowing the ball sealer through the fluid flow conduit and locating the ball sealer on an existing perforation that is downhole from the autonomous perforation device; and (iii) closing a valve that forms a portion of the autonomous perforation device to restrict flow of the stimulant fluid stream past the autonomous perforation device.
 5. The method of claim 3, wherein the perforating further includes releasing a sealing material into the casing conduit, wherein the releasing includes at least one of: (i) releasing at least one ball sealer from the autonomous perforation device; (ii) releasing a supplemental sealing material from the autonomous perforation device; and (iii) breaking apart the autonomous perforation device to form the sealing material.
 6. The method of claim 1, wherein the autonomous perforation device is a first autonomous perforation device, wherein the target region of the casing conduit is a first target region of the casing conduit, wherein the fluid flow conduit is a first fluid flow conduit, wherein the portion of the subterranean formation is a first portion of the subterranean formation, and further wherein the method includes: flowing, with the carrier fluid stream, a second autonomous perforation device within the casing conduit; retaining the second autonomous perforation device within a second target region of the casing conduit, wherein the second target region is uphole from the first target region; flowing the stimulant fluid stream past the second autonomous perforation device via a second fluid flow conduit that is at least partially defined by the second autonomous perforation device; and stimulating, with the stimulant fluid stream, a second portion of the subterranean formation that is downhole from the second autonomous perforation device.
 7. The method of claim 1, wherein the retaining includes expanding the autonomous perforation device from a retracted configuration to an expanded configuration.
 8. The method of claim 1, wherein the retaining includes retaining with a motion-arresting assembly that forms a portion of the autonomous perforation device, and further wherein the retaining includes at least one of: (i) operatively engaging at least a portion of the motion-arresting assembly with a projection that extends within the casing conduit; and (ii) operatively engaging the motion-arresting assembly with the casing string.
 9. The method of claim 1, wherein the stimulant fluid stream is the carrier fluid stream.
 10. The method of claim 1, wherein the stimulant fluid stream is different from the carrier fluid stream.
 11. The method of claim 10, wherein the stimulant fluid stream includes particulate material and the carrier fluid stream is at least substantially free of particulate material.
 12. An autonomous perforation device configured to be flowed within a casing conduit that is defined by a casing string within a subterranean formation, the autonomous perforation device comprising: a perforation assembly; a motion-arresting assembly configured to be selectively actuated to retain the autonomous perforation device within a target region of the casing conduit; and a fluid flow conduit defined at least in part by the autonomous perforation device, wherein the fluid flow conduit permits fluid flow between a portion of the casing conduit that is uphole from the autonomous perforation device and a portion of the casing conduit that is downhole from the autonomous perforation device when the autonomous perforation device is retained within the target region of the casing conduit.
 13. The device of claim 12, wherein the perforation assembly includes a perforation gun that includes at least one perforation charge.
 14. The device of claim 12, wherein the perforation assembly is an autonomous perforation assembly configured to autonomously create a perforation within the casing string responsive to a wellbore pressure within the casing conduit proximal to the autonomous perforation device exceeding a threshold perforating pressure.
 15. The device of claim 12, wherein the perforation assembly is configured to create a perforation within the casing string responsive to receipt of a perforation signal.
 16. The device of claim 12, wherein the motion-arresting assembly defines a retracted configuration, in which the motion-arresting assembly permits the autonomous perforation device to flow within the casing conduit, and an expanded configuration, in which the motion-arresting assembly restricts motion of the autonomous perforation device within the casing conduit, and further wherein the motion-arresting assembly is configured to be selectively transitioned from the retracted configuration to the expanded configuration to retain the autonomous perforation device within the target region of the casing conduit.
 17. The device of claim 12, wherein the motion-arresting assembly is an autonomous motion-arresting assembly configured to autonomously retain the autonomous perforation device within the target region of the casing conduit responsive to a retention criterion.
 18. The device of claim 17, wherein the retention criterion includes at least one of: (i) a pressure within the casing conduit proximal to the autonomous perforation device exceeding a threshold retention pressure; (ii) the autonomous perforation device being present within the target region of the casing conduit; (iii) the autonomous perforation device flowing along a target length of the casing conduit; and (iv) the autonomous perforation device flowing through a target number of casing collars.
 19. The device of claim 12, wherein the motion-arresting assembly is configured to retain the autonomous perforation device within the target region of the casing conduit responsive to receipt of a retention signal.
 20. The device of claim 12, wherein the autonomous perforation device includes a plurality of fluid flow conduits that each permits a respective fluid flow between the portion of the casing conduit that is uphole from the autonomous perforation device and the portion of the casing conduit that is downhole from the autonomous perforation device.
 21. The device of claim 12, wherein the autonomous perforation device includes a plurality of fins that at least partially define the fluid flow conduit.
 22. The device of claim 12, wherein the autonomous perforation device further includes a fluid flow conduit sealing assembly that is configured to selectively restrict fluid flow through the fluid flow conduit.
 23. The device of claim 22, wherein the fluid flow conduit sealing assembly includes a valve that is configured to selectively transition between an open configuration, in which the valve permits the fluid flow through the fluid flow conduit, and a closed configuration, in which the valve restricts the fluid flow through the fluid flow conduit.
 24. The device of claim 22, wherein the fluid flow conduit sealing assembly includes a ball sealer seat that is defined by the autonomous perforation device and that is configured to selectively restrict the fluid flow through the fluid flow conduit responsive to receipt of a ball sealer.
 25. The device of claim 12, wherein the autonomous perforation device includes a storage structure that is configured to selectively release a sealing material.
 26. The device of claim 12, wherein the autonomous perforation device further includes an autonomous control assembly that is configured to autonomously control the operation of at least a portion of the autonomous perforation device.
 27. The device of claim 26, wherein the autonomous control assembly is configured to at least one of: (i) actuate the perforation assembly; (ii) actuate the motion-arresting assembly; and (iii) selectively restrict the fluid flow through the fluid flow conduit.
 28. A hydrocarbon well, comprising: the autonomous perforation device of claim 12; a wellbore that extends within the subterranean formation; and a casing string, wherein the casing string extends within the wellbore, and further wherein the autonomous perforation device is located within the casing conduit.
 29. The hydrocarbon well of claim 28, wherein the casing conduit further includes a plurality of projections that extend within the casing conduit to define a plurality of reduced-area regions of the casing conduit, and further wherein the motion-arresting assembly is operatively engaged with a selected one of the plurality of projections. 